This invention relates to a method and apparatus for forming a layer of blown cellular urethane on a carpet backing, and to a carpet having an integral blown cellular urethane cushion.
Heretofore, as exemplified by the apparatus disclosed in U.S. Pat. Nos. 3,700,515; 3,705,834; 3,806,385; 3,834,961; which patents are assigned to assignee of the present application, and the following patents which are assigned to others--U.S. Pat. Nos. 2,950,221; 3,047,449; 3,123,508; 3,175,936; 3,206,343; 3,219,502; 3,257,483; 3,240,655; 3,453,168; 3,519,526; 3,686,046; 3,730,822; 3,772,224; 3,849,156; 3,862,879; 3,874,964; 3,926,700; 3,947,386; 3,959,191; 2,993,813; 3,013,924; 3,034,942; 3,046,177; 3,085,896; 3,181,199; 3,269,882; 3,399,107; 3,475,522; 3,650,880; 3,748,217; 3,844,862; 3,923,938; 3,939,235; 3,941,633; German Pat. Nos. 1,469,534; 1,952,397; 2,255,149; 2,208,995; 1,917,424; 1,948,527; 1,619,583; and 2,223,658; methods and apparatuses have been devised for forming urethane foam cushions or pads on fabric carpet backings. None of these previous methods or apparatuses has proven satisfactory and none has achieved any significant commercial success. In many of the previous methods, the unreacted urethane reactants are applied directly to the underside of the carpet primary backing. The primary backing has tuft loops or weave strands exposed on and protruding from its underside. The texture and porosity of these backings has limited the effectiveness of the application method which in turn has resulted in the formation of carpet cushions of uneven thickness once the urethane has expanded and cured.
Accordingly, it is an object of the present invention to provide an improved method for forming a layer of blown cellular urethane on a carpet fabric backing.
Another object of the invention is to provide improved apparatus for forming a layer of blown cellular urethane on a carpet fabric backing.
Yet another object of the invention is to provide an improved carpet of the type having a layer of blown cellular urethane on its underside.
These and other objects, features and advantages of the present invention will be apparent from reviewing the following more detailed description of the invention.